Theory of Machines – Mechanical Engineering Multiple Choice Questions
101. An eccentric sheave pivoted at one point rotates and transmits oscillatory motion to a link whose one end is pivoted and other end is connected to it. This mechanism has
(a) 2 links
(b) 3 links
(c) 4 links
(d) 5 links
(e) none of the above.
Ans: c
102. Whitworth quick return mechanism is obtained by inversion of
(a) slider crank mechanism
(b) kinematic chain
(c) five link mechanism
(d) roller cam mechanism
(e) none of the above.
Ans: a
103. In its simplest form, a cam mechanism consists of following number of links
(a) 1
(b) 2
(c) 3
(d) 4
(e) none.
Ans: c
104. Which of the following mechanisms produces mathematically an exact straight line motion
(a) Grasshopper mechanism
(b) Watt mechanism
(c) Peaucellier’s mechanism
(d) Tchabichiff mechanism
(e) Ackermann mechanism.
Ans: c
105. In a mechanism, usually one link is fixed. If the fixed link is changed in a kinematic chain, then relative motion of other links
(a) will remain same
(b) will change
(c) could change or remain unaltered depending oh which link is fixed
(d) will not occur
(e) none of the above.
Ans: a
106. A kinematic chain requires at least
(a) 2 links and 3 turning pairs
(b) 3 links and 4 turning pairs
(c) 4 links and 4 turning pairs
(d) 5 links and 4 turning pairs
(e) none of the above.
Ans: c
107. In a darg link quick return mechanism, the shortest link is always fixed. The sum of the shortest and longest link is
(a) equal to sum of other two
(b) greater than sum of other two
(c) less than sum of other two
(d) there is no such relationship
(e) none of the above.
Ans: c
108. The following is the inversion of slider crank chain mechanism
(a) Whit worth quick return mechanism
(b) hand pump
(c) oscillating cylinder engine
(d) all of the above
(e) none of the above.
Ans: d
109. Kinematic pairs are those which have
(a) two elements held together mechanically
(b) two elements having relative motion
(c) two elements having Coroili’s component
(d) minimum of two instantaneous centers
(e) all of the above.
Ans: b
110 A typewriter mechanism has 7 number of binary joints, six links and none of higher pairs. The mechanism is
(a) kinematic ally sound
(b) not sound
(c) soundness would depend upon which link is kept fixed
(d) data is not sufficient to determine same
(e) none of the above.
Ans: a
111. In a four-bar chain it is required to give an oscillatory motion to the follower for a continuous rotation of the crank. For the lengths of 50 mm of crank and 70 mm of the follower, determine theoretical maximum length of coupler. The distance between fixed pivots of crank and followers is
(a) 95 mm
(b) slightly less than 95 mm
(c) slightly more than 95 mm
(d) 45 mm
(e) none of the above.
Ans: b
112. In above example, the minimum length of the coupler will be
(a) 45 mm
(b) slightly less than 45 mm
(c) slightly more than 45 mm
(d) 95 mm
(e) none of the above.
Ans: c
113. In S.H.M., acceleration is proportional to
(a) velocity
(b) displacement
(c) rate of change of velocity
(d) all of the above
(e) none of the above.
Ans: b
114. For simple harmonic motion of the of follower, a cosine curve represents
(a) displacement diagram
(b) velocity diagram
(c) acceleration diagram
(d) all of the above
(e) none of the above.
Ans: c
115. In S.H.M., the velocity vector w.r.t. displacement vector
(a) leads by 90°
(b) lags by 90°
(c) leads by 180°
(d) are in phase
(e) could be anywhere.
Ans: a
116. A body having moment of inertia o:m2 is rotating at 210 RPM and r with another body at rest having 40 kg m2. The resultant speed after will be
(a) 90 RPM
(b) 100 RPM
(c) 80 RPM
(d) data are insufficient
(e) none of the above.
Ans: a
117. Inertia force acts
(a) perpendicular to the accelerate force
(b) along the direction of accelerate force
(c) opposite to the direction of accelerate force
(d) in any direction w.r.t. accelerate force depending on the magnet two
(e) none of the above.
Ans: c
118. The frequency of oscillation at compared to earth will be
(a) 6 times more
(b) 6 times less
(c) 2.44 times more
(d) 2.44 times,less
(e) 36 times less.
Ans: d
119. Angle of ascent of cam is defined as the angle
(a) during which the follower returns to its initial position
(b) of rotation of the cam for a definite displacement of the follower
(c) through which the cam rotates during the period in which the follower remains in highest position
(d) moved by the cam from the instant the follower begins to rise, till it reaches its highest position
(e) moved by the cam from beginning of ascent to the termination of descent.
Ans: d
120. If the radius of gyration of a compound pendulum about an axis through e.g. is more, then its frequency of oscillation will be
(a) less
(b) more
(c) same
(d) data are insufficient to determine same
(e) none of the above.
Ans: a
121. The Bifilar suspension method is used to determine
(a) natural frequency of vibration
(b) position of balancing weights
(c) moment of inertia
(d) centripetal acceleration’
(e) angular acceleration of a body.
Ans: c
122. Which is the false statement about the properties of instantaneous center
(a) at the instantaneous center of rotation, one rigid link rotates instantaneously relative to another for the configuration of mechanism considered
(b) the two rigid links have no linear velocities relative to each other at the instantaneous center
(c) the two rigid links which have no linear velocity relative to each other at this center have the same linear velocity to the third rigid link
(d) the double center can be denoted either by 02\ or Ol2, but proper selection should be made
(e) none of the above.
Ans: d
123. Instantaneous center of rotation of a link in a four bar mechanism lies on
(a) right side pivot of this link
(b) lift side pivot of this link
(c) a point obtained by intersection on extending adjoining links
(d) can’t occur
(e) none of the above.
Ans: c
124. The number of links and instantaneous centers in a reciprocating engine mechanism are
(a) 4, 4
(b) 4, 5
(c) 5, 4
(d) 6, 4
(e) 4, 6
Ans: e
125. According to Kennedy’s theorem, if three bodies have plane motions, their instantaneous centers lie on
(a) a triangle
(b) a point
(c) two lines
(d) a straight line
(e) a curve.
Ans: d